What is a water treatment chemical?

Water treatment chemicals are substances used in water purification processes, primarily functioning to improve water quality by removing harmful substances, pollutants, bacteria, and viruses to achieve water source purification. These chemicals are widely applied in industrial, agricultural, domestic, environmental protection, drinking water, and wastewater treatment sectors. Through various chemical reactions, physical interactions, and biodegradation processes, they help eliminate harmful components in water, ensuring its safety and usability.

As global environmental challenges intensify, the demand for water pollution control grows increasingly urgent. The application of water treatment chemicals not only effectively addresses sewage and wastewater issues but also enhances water resource utilization efficiency, playing a crucial role in ecological conservation and human health.

1. Primary Types of Water Treatment Chemicals

Water treatment chemicals can be categorized into various types based on specific application requirements. Common types include:

(1) Flocculants

- Function: Destabilizes colloids and suspended solids in water, causing them to aggregate into larger flocs for easier sedimentation or filtration removal.

Inorganic flocculants: Polyaluminum chloride (PAC), aluminum sulfate, ferric chloride, etc.;

Organic polymer flocculants: Polyacrylamide (PAM, available in anionic, cationic, and nonionic types);

Composite flocculants: PAC+PAM blends, suitable for challenging wastewater.

- Applications: Water treatment plants, sewage treatment, industrial wastewater pretreatment, RO system pretreatment.

(2) Scale Inhibitors

- Function: Prevents scaling ions like calcium, magnesium, barium, and silica from precipitating and forming deposits on equipment or membrane surfaces.

Organophosphonic acids (e.g., HEDP, ATMP);

Polycarboxylic acids (e.g., PAA, AA/AMPS copolymers);

Composite scale inhibitors (combining dispersion, chelation, and threshold effects).

- Applications: Reverse osmosis (RO), circulating cooling water, boiler feedwater, seawater desalination systems.

(3) Corrosion Inhibitors

- Function: Form protective films on metal surfaces to inhibit electrochemical corrosion.

Molybdate, tungstate (environmentally friendly);

Organic amines, azoles (e.g., BTA for copper corrosion inhibition);

Phosphates (traditional, but prone to causing eutrophication).

- Applications: Circulating water systems, boilers, central air conditioning, oilfield reinjection water.

(4) Biocides and Algaecides

- Function: Control microbial (bacteria, algae, fungi) growth to prevent biofouling and bio-corrosion.

Oxidizing biocides: Sodium hypochlorite, chlorine dioxide, ozone (highly effective but may damage RO membranes);

Non-oxidizing biocides: DBNPA, isothiazolinone, glutaraldehyde (membrane-friendly, suitable for shock dosing).

- Applications: Cooling towers, RO feedwater, oilfields, paper mill white water systems.

(5) Cleaners

- Function: Remove existing deposits, organic matter, biofilms, or inorganic scale.

Acidic cleaners: Citric acid, aminosulfonic acid (removes inorganic scale);

Alkaline cleaners: NaOH + surfactants (removes organic matter, oil, biofilms);

Composite cleaners: Addresses multiple contaminants.

- Applications: Periodic maintenance cleaning of RO membranes, ultrafiltration membranes, heat exchangers, and boilers.

(6) Defoamers

- Function: Eliminate or suppress foam generated during water treatment processes.

Types: Silicone-based, polyether-based, high-carbon alcohol polyether-based, mineral oil-based;

Silicone-free types suitable for sensitive sectors like electronics, food processing, and high-end coatings.

- Applications: Bioreactors, MBR membrane systems, cleaning tanks, pesticide formulation, papermaking.

(7) pH Adjusters

- Function: Modulate water acidity/alkalinity to optimize chemical efficacy or meet discharge standards.

Acidic adjusters: Sulfuric acid, hydrochloric acid, citric acid;

Alkaline adjusters: Sodium hydroxide, sodium carbonate, ammonia solution.

- Applications: Neutralization reactions, RO feedwater pH control (preventing CaCO₃ scaling), wastewater compliance discharge.

(8) Specialized Functional Chemicals

Deoxidizers: Sodium bisulfite, hydrazine (for removing dissolved oxygen from boiler feedwater);

Heavy Metal Capturers: DTC-type agents, sodium sulfide (for electroplating and metallurgical wastewater);

Decolorizing Agents: Dicyandiamide-formaldehyde resin, polymeric ferric sulfate (for dyeing wastewater);

Sludge Conditioners: Cationic PAM (enhances dewatering efficiency)

2. Primary Functions of Water Treatment Chemicals

(1) Water Purification: Water treatment chemicals effectively remove pollutants such as suspended solids, bacteria, viruses, and heavy metals from water sources, ensuring cleanliness and hygiene.

(2) Scale and Corrosion Prevention: Certain chemicals prevent scale buildup inside pipes and equipment, extending equipment lifespan while inhibiting mineral deposits and corrosion.

(3) Disinfection and Sterilization: Sterilizing agents eliminate bacteria, algae, and viruses in water to guarantee water safety. They are widely used in drinking water, swimming pools, industrial water treatment, and other applications.

(4) Enhancing Water Usage Efficiency: Water treatment chemicals facilitate water recycling and reuse, reducing dependence on natural water resources and promoting water resource circulation. They are particularly prevalent in industrial and agricultural irrigation.

(5) Adjusting Water Properties: Certain agents regulate pH, hardness, salinity, and other characteristics to optimize water conditions, preventing equipment clogging and damage.

3. Environmental Sustainability of Water Treatment Agents

As global environmental awareness grows, the eco-friendliness and safety of water treatment agents have become focal points. Modern formulations prioritize reduced chemical usage, minimized residual pollutants in water bodies, and advancement of green water treatment technologies.

(1) Low Toxicity: Green water treatment chemicals are designed with low toxicity to minimize harm to aquatic life and prevent negative ecological impacts from chemicals during treatment.

(2) Biodegradability: Modern formulations prioritize biodegradable chemical components to ensure wastewater discharge does not cause long-term environmental pollution.

(3) Non-Residual: Certain agents undergo specialized processing to eliminate harmful residues post-use, effectively preventing secondary contamination.

4. Application Fields of Water Treatment Chemicals

(1) Drinking Water Treatment: Water treatment chemicals play a critical role in purifying, disinfecting, and sterilizing drinking water, ensuring water quality meets sanitary standards and preventing water source contamination.

(2) Industrial Water Treatment: In industrial production processes, water treatment chemicals are used for cooling water, boiler water, and wastewater treatment to prevent equipment corrosion, scaling, and pollutant discharge, thereby reducing environmental pollution.

(3) Sewage Treatment: Water treatment agents purify and treat wastewater, effectively removing harmful substances, reducing pollutant discharge, and protecting aquatic environments.

(4) Agricultural Water Treatment: In agricultural irrigation, water treatment agents regulate water quality, prevent water source contamination, and enhance the operational efficiency of farmland water conservancy facilities.

(5) Swimming Pool Water Treatment: Water treatment agents are widely used in swimming pools and water recreation facilities to ensure water cleanliness and prevent bacterial and algal growth.

(6) Household Water Treatment: Water treatment agents are commonly used in homes to purify drinking water, remove scale, and clean appliances, ensuring the safety of domestic water supplies.

5. Market Prospects for Water Treatment Agents

As global water resource challenges intensify, market demand for water treatment agents continues to grow. Needs in water pollution control, sewage treatment, and wastewater recycling will further increase. In the future, driven by refined environmental policies and innovations in water treatment technology, water treatment agents will evolve toward greater efficiency, environmental sustainability, and cost-effectiveness.

(1) Intelligent Water Treatment: Driven by advancements in information technology and artificial intelligence, water treatment agents will become smarter and more automated, enabling real-time monitoring and optimized adjustments.

(2) Eco-Friendly Water Treatment Agents: Environmentally sustainable agents will dominate the market, featuring enhanced biodegradability, low toxicity, and minimal residual harm to reduce environmental impact.

(3) Energy-Efficient Water Treatment: Energy-saving agents will emerge as a key market trend, improving treatment efficiency while minimizing resource waste.

As an indispensable component of modern water treatment technology, water treatment agents significantly advance water purification, wastewater management, and water resource recycling through their high efficiency and broad functionality. With technological progress and heightened environmental demands, the variety and capabilities of water treatment agents will continue to expand, alongside their application scope. In the future, water treatment agents will play an increasingly vital role, making greater contributions to global water environmental protection and the sustainable utilization of water resources.